Question

The side of square is increased by 10%. By what % does the area increase?​

Answer 1

Answer:

Step-by-step explanation:

Let original side = a

Original area. = a^2

New side = a + 10% of a = 1.1a

New area = (1.1a)^2 = 1.21a^2

Increase in area

= 1.21a^2 - a^2 = 0.21a^2

Increase% = 0.21a^2×100/a^2

= 21% Answer.

(2)Another easiest technique/

Let side = 10

Original area = (10)^2 = 100

New side = 10 + 10% of 10 = 11

New area = (11)^2 = 121

Increase in area

= 121-100 = 21

increase % = 21×100/100

= 21% Answer